System and method for dynamically determining multimedia transmission based on communication bandwidth

ABSTRACT

A system and method is provided for dynamically adjusting one or more characteristics of a multimedia transmission between a content provider and a content recipient. In one embodiment, the system responds to a change in available bandwidth between the content provider and the content recipient.

This application is a continuation of U.S. patent application Ser. No.10/742,851, filed Dec. 23, 2003, which is currently allowed and isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to multimedia systems andmethods and, more particularly, to a system and method for dynamicallydetermining multimedia transmission based on communication bandwidth.

INTRODUCTION

The increasing accessibility to the Internet has fueled a correspondingincrease in the accessibility of multimedia content. Users are becomingincreasingly accustomed to accessing various forms of multimedia contentsuch as movie trailers, news clips, sporting highlights, etc. As is wellknown, the user experience in accessing various forms of multimediacontent is highly dependent on the bandwidth capacity of a user'snetwork Internet connection.

Traditional dial-up connections at 56 k have continued to represent thedominant form of user access to the network (e.g., Internet). Whilehigher bandwidth integrated services digital network (ISDN) serviceshave existed for some time, only recently have cable, satellite anddigital subscriber line (DSL) service providers been able tosignificantly accelerate the proliferation of broadband network access.

Broadband network access has enabled significant improvements with auser's experience in accessing multimedia content. A most notableexample is the support of higher frame resolution levels through thehigher bandwidth connections.

As a user's network connection has significant implications on hisexperience with multimedia content, what is needed is a mechanism thatmaximizes a user's experience based on the available bandwidth.

SUMMARY

In accordance with the present invention, a process is provided fordynamically adjusting one or more characteristics of a multimediatransmission between a content provider and a content recipient. In oneembodiment, the system responds to a change in available bandwidthbetween the content provider and the content recipient.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth herein.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and otheradvantages and features of the invention can be obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 illustrates an embodiment of a system of the present invention;and

FIG. 2 illustrates a flowchart of a method of the present invention.

DETAILED DESCRIPTION

Various embodiments of the invention are discussed in detail below.While specific implementations are discussed, it should be understoodthat this is done for illustration purposes only. A person skilled inthe relevant art will recognize that other components and configurationsmay be used without parting from the spirit and scope of the invention.

As noted, a wide range of network access options are currently availableto users. With the accelerating proliferation of broadband cable or DSLconnections, users are becoming increasingly familiar with the benefitsof higher bandwidth connections. These benefits are significant whenevermultimedia content is being accessed.

Due to the range of connection speeds that currently exist amongstusers, many applications rely on a user's specification of connectionspeed to dictate the quality of the multimedia experience. For example,when a content provider makes a streaming video (e.g., movie trailer)available to various users (or content recipients), the content providerfirst presents the user with various choices of media resolution (e.g.,small, medium, large) before commencing with delivery of the multimediastream. This choice by the user is typically based on the bandwidth ofthe user's connection. If the user is on a dial-up connection, then thesmallest resolution will be most suitable. Conversely, if the user is ona high-bandwidth cable connection, then the largest resolution may besuitable.

If the user selects a resolution that is unsupportable by the user'sconnection, then the multimedia experience will be less thansatisfactory resulting in a multimedia stream that can skip, jump, orhalt. Unfortunately, once the user has made a selection, the user isstuck with that particular resolution for the duration of the multimediastream. Modification to the selection can be effected by restarting themultimedia stream.

It should be noted that unsatisfactory results in viewing multimediacontent are not restricted with those users that are hampered bylow-bandwidth connections. Even high-bandwidth users can haveunsatisfactory results when viewing a multimedia stream. This fact is aconsequence of variations in a user's connection bandwidth. Thesevariations can depend on many aspects of a network connection (e.g.,Internet, private network, or the like), such as packet loss, packetcollision, sharing of common transport, etc., and can prevent theconnection from operating at its ideal top-rated speed.

Accounting for these variations in bandwidth can result in a less thanideal multimedia experience. For example, when faced with a choice ofresolutions, a user may select a lower resolution that he believes wouldbe sufficient to accommodate potential drops in connection bandwidth.This choice would often be driven by a user's desire to ensure a smoothplayback of the multimedia stream. As would be appreciated, this initialuser choice would result in a resolution that would often be lower thana resolution level that could be sustained for good portions of themultimedia stream.

It is therefore a feature of the present invention that a user'smultimedia experience can be maximized with respect to a user'savailable connection bandwidth. As described in greater detail below,this maximization is based on a dynamic adjustment mechanism that canmodify characteristics of a multimedia stream during the playback of themultimedia stream. These modifications can be in response to a decreaseor an increase in available connection bandwidth.

To illustrate the various features of the present invention, referenceis made first to the system diagram of FIG. 1. As illustrated in FIG. 1,multimedia system 100 includes a content provider 110, a contentrecipient 130, and one or more controlling servers 120. Here, contentprovider 110 can represent any system on a network that operates as asource of multimedia content, while content recipient 130 can representany system on the network that receives the multimedia content viamultimedia transmission channel 146. Here, it should be noted that inthe context of a generic point-to-point connection between two users(e.g., video call), each user could functionally operate as both acontent provider and a content recipient in the two-way multimediatransmission. In this scenario, changes in the available bandwidth ofthe connection would produce an impact on both ends of the connection.

As illustrated in FIG. 1, controlling servers 120 can represent anycollection of one or more systems that assist in the establishment of aconnection between content provider 110 and content recipient 130. Aspart of this process, controlling servers 120 communicate with contentprovider 110 and content recipient 130 via signaling channels 142 and144, respectively. In general, signaling channels 142, 144 enable anexchange of information that can be used to set up multimediatransmission channel 146 for use between content provider 110 andcontent recipient 130.

In one embodiment, signaling between controlling servers 120 and contentprovider 110 and content recipient 130 are based on the SessionInitiation Protocol (SIP), which is the Internet Engineering TaskForce's (IETF's) standard for multimedia conferencing over IP. Ingeneral, SIP is an ASCII-based, application layer control protocol thatcan be used to establish, maintain, and terminate connections betweentwo or more end points. SIP is described in greater detail in RFC2543—SIP: Session Initiation Protocol, which is incorporated byreference herein in its entirety.

In general, the dynamic adjustment mechanism of the present inventionoperates to adjust, during an established multimedia transmission, oneor more characteristics of the multimedia transmission that can affectthe bandwidth required to accommodate the multimedia transmission. Inone embodiment, three characteristics of the multimedia stream can beadjusted either alone or in combination: the video resolution level, theframe rate, and the audio compression level. The basis for thisadjustment and the specific form of the adjustment is dependent on arecognized change in the bandwidth available to support the multimediatransmission.

In one embodiment, the available bandwidth is determined through thedetection of the current transmission level between content provider 110and content recipient 130. This detection process can be embodied invarious forms and in various parts of the network. For example, thedetection process can be based on a monitoring of packets as theytraverse the network. In general, as multimedia transmission channel 146can traverse multiple networks, specific measures of network performancecan be gained at various points in various networks to determine thebandwidth bottleneck. Regardless of where the information is generated,the ultimate provision of its detection to one of the controllingservers 120 enables a dynamic adjustment mechanism to be effected.

To illustrate this process, reference is made to the flowchart of FIG.2. As illustrated, the process begins at step 202 where a connection isestablished between content provider 110 and content recipient 130. Asnoted, in one embodiment, the connection can be a SIP-based connection.As part of this process, controlling server(s) 120 can be used todetermine the media capabilities of content provider 110 and contentrecipient 130. Here, the Session Description Protocol (SDP) can be usedto assist in the determination of the lowest level of common services(e.g., connection bandwidth) between content provider 110 and contentrecipient 130. Based on this determined lowest level of common services,characteristics (e.g., video resolution level, frame rate, and audiocompression level) of the multimedia transmission can then bedetermined.

After the connection has been established, the process continues to step204 where the bandwidth between content provider 110 and contentrecipient 130 is monitored. If it is determined at step 206 that nochanges in bandwidth are detected, then the monitoring processcontinues. If it is determined at step 206 that a change in bandwidth(higher or lower) is detected in any part of the network supportingmultimedia transmission channel 146, then a dynamic adjustment processis invoked.

As noted above, the change in bandwidth between content provider 110 andcontent recipient 130 can be detected by monitoring elements at variouspoints in the network. This detection represents an actual change inbandwidth between content provider 110 and content recipient 130.

It should be noted, however, that a bandwidth change can also be theresult of a self-imposed constraint adopted by either content provider110 or content recipient 130. For example, assume that content provider110 recognizes that a portion of his outgoing bandwidth is needed fordelivery of additional data to content recipient 130. As would beappreciated, this additional data can be part of the same session as themultimedia transmission or can be part of an entirely different session.Regardless, this additional data delivery will use up a portion of thebandwidth dedicated to content recipient 130 and may therefore requirean adjustment in one or more characteristics of the multimediatransmission to accommodate the transmission of the additional data. Ingeneral, any delivery of additional data to content recipient 130 or toanother party could impact the outgoing bandwidth from content provider110 and would therefore necessitate a change in the multimediatransmission to content recipient 130.

Regardless of the cause, a change in bandwidth detected at step 206 willlead to the dynamic adjustment process beginning at step 208.Specifically, at step 208, a modification to one or more characteristicsof the established connection is identified. In one embodiment, thesecharacteristics include the video resolution level, the frame rate andthe audio compression level.

Each of these characteristics can be defined at discrete levels, thetransitions between which will involve a positive or negative change inrequired bandwidth. These positive and negative changes in bandwidth canbe used to determine the needed modifications to accommodate thedetected change in bandwidth. As would be appreciated, these changes forparticular characteristics can be evaluated independently or incombination.

Consider for example a system that can implement the following discretelevels of multimedia transmission characteristics: video resolutionlevels of 176×144, 320×240 and 640×480; frame rates of 5, 10, 15, and 30frames/sec; and audio compression levels of 8 kbps (based on the G.729codec) and 64 kbps (based on the G. 711 codec). Assume further that themultimedia transmission is initially established at video resolution of320×240, a frame rate of 30, and an audio compression level of 8 kbps.

If it is detected that an increase in available bandwidth has occurred,then the system could determine that the video resolution level can beincreased to 640×480. If, however, the system determines that theincrease in bandwidth would not support an increase in the videoresolution level to 640×480, then the system could then choose todecrease the audio compression level to 64 kbps, thereby increasing thesound quality of the transmission. Of course, if the bandwidth changecan accommodate both an increase in the video resolution level to640×480 and a decrease in the audio compression level, then both ofthose modification could be effected.

If it is detected that a decrease in available bandwidth has occurred,then the system could determine that the video resolution level and/orthe frame rate should be decreased. The specific amount of the decreasein the video resolution level and/or the frame rate would be based onthe amount of the reduction in available bandwidth. For example, if alarge decrease in available bandwidth is detected, the system couldchoose to reduce the video resolution level to 176×144 and the framerate to 5 frames/sec. In an extreme case, where the available bandwidthis drastically cut, the system could also choose to eliminate the videoportion of the stream altogether and transmit only the audio component.

While various methods of adjustment can be used in balancing the changesin the video resolution level, the frame rate and the audio compressionlevel, one of the goals of the process is to maintain a smoothmultimedia stream. This goal can dictate a combination of changes thatwould be more permissible than others. For example, the system could bedesigned to reduce the video resolution levels before it reduced theframe rate. As would be appreciated, the specific methods of adjustmentwould be implementation dependent and would not alter the principles ofthe present invention.

In one embodiment, either party to the connection can place their ownconstraints on the methodology by which the adjustments are to be made.To illustrate this concept consider a general point-to-point connectionbetween two users (A and B). In this scenario, either party could notonly decide whether to place an artificial constraint on the availablebandwidth, but also decide the methodology by which the adjustments toone or more of the video resolution level, the frame rate and the audiocompression level are made. For example, user A could choose tosacrifice the video resolution level first and the audio compressionlevel last upon a change (actual or self imposed by user A) inbandwidth, while user B could choose to sacrifice the video frame ratefirst and the video resolution level last upon a change (actual or selfimposed by user B) in bandwidth. These options can be entered into thesystem as user-selectable preferences.

After the modifications are determined at step 208, the modificationsare then placed in effect at step 210. More specifically, theestablished connection is modified in midstream in a process governed bycontrolling server 120. This midstream modification would seek tomaximize the user's experience given the current bandwidth constraints.Here, it is significant that the characteristics of the multimediatransmission occur automatically without relying on a user'sspecification.

Embodiments within the scope of the present invention may also includecomputer-readable media for carrying or having computer-executableinstructions or data structures stored thereon. Such computer-readablemedia can be any available media that can be accessed by a generalpurpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium which can be used to carryor store desired program code means in the form of computer-executableinstructions or data structures. When information is transferred orprovided over a network or another communications connection (eitherhardwired, wireless, or a combination thereof) to a computer, thecomputer properly views the connection as a computer-readable medium.Thus, any such connection is properly termed a computer-readable medium.Combinations of the above should also be included within the scope ofthe computer-readable media.

Computer-executable instructions include, for example, instructions anddata which cause a general purpose computer, special purpose computer,or special purpose processing device to perform a certain function orgroup of functions. Computer executable instructions also includeprogram modules that are executed by computers in stand-alone or networkenvironments. Generally, program modules include routines, programs,objects, components, and data structures, etc. that perform particulartasks or implement particular abstract data types. Computer-executableinstructions, associated data structures, and program modules representexamples of the program code means for executing steps of the methodsdisclosed herein. The particular sequence of such executableinstructions or associated data structures represents examples ofcorresponding acts for implementing the functions described in suchsteps.

Those of skill in the art will appreciate that other embodiments of theinvention may be practiced in network computing environments with manytypes of computer system configurations, including personal computers,hand-held devices, multi-processor systems, microprocessor-based orprogrammable consumer electronics, network PCs, minicomputers, mainframecomputers, and the like. Embodiments may also be practiced indistributed computing environments where tasks are performed by localand remote processing devices that are linked (either by hardwiredlinks, wireless links, or by a combination thereof) through acommunications network. In a distributed computing environment, programmodules may be located in both local and remote memory storage devices.

Although the above description may contain specific details, they shouldnot be construed as limiting the claims in any way. Other configurationsof the described embodiments of the invention are part of the scope ofthis invention. Accordingly, the appended claims and their legalequivalents only should define the invention, rather than any specificexamples given.

1. A method of dynamically adjusting a multimedia transmission between acontent provider and a content recipient, comprising: receiving anindication of a change in an available bandwidth between the contentprovider and the content recipient during an established multimediatransmission of a multimedia stream that occurs at a video resolutionlevel, and an audio compression level; determining, based on the changein the available bandwidth, an adjustment to at least of: the videoresolution level or the audio compression level of the multimediastream; and coordinating, via a server, the adjustment in the multimediastream between the content provider and the content recipient in theestablished multimedia transmission.
 2. The method of claim 1, whereinthe indication is an indication of a monitored change in the availablebandwidth between the content provider and the content recipient.
 3. Themethod of claim 1, wherein the indication is an indication of a selfimposed reduction in bandwidth.
 4. The method of claim 1, wherein theadjustment comprises an adjustment only to the video resolution level.5. The method of claim 1, wherein the adjustment comprises an adjustmentonly to the audio compression level.
 6. The method of claim 1, whereinthe adjustment comprises an adjustment to the video resolution level,the audio compression level and a frame rate.
 7. The method of claim 1,wherein the server is a network server.
 8. The method of claim 7,wherein the network server employs a session initiation protocol forsignaling.
 9. The method of claim 1, wherein the server is operated bythe content provider.
 10. The method of claim 1, wherein the adjustmentaccounts for a selected preference of the content recipient.
 11. Anon-transistory computer-readable medium that stores a program forcontrolling a device to perform a method of dynamically adjusting amultimedia transmission between a content provider and a contentrecipient, comprising: receiving an indication of a change in anavailable bandwidth between the content provider and the contentrecipient during an established multimedia transmission of a multimediastream that occurs at a video resolution level, and an audio compressionlevel; determining, based on the change in the available bandwidth, anadjustment to at least of: the video resolution level or the audiocompression level of the multimedia stream; and coordinating, via aserver, the adjustment in the multimedia stream between the contentprovider and the content recipient in the established multimediatransmission.
 12. The non-transistory computer-readable medium of claim11, wherein the indication is an indication of a monitored change in theavailable bandwidth between the content provider and the contentrecipient.
 13. The non-transistory computer-readable medium of claim 11,wherein the indication is an indication of a self imposed reduction inbandwidth.
 14. The non-transistory computer-readable medium of claim 11,wherein the adjustment comprises an adjustment only to the videoresolution level.
 15. The non-transistory computer-readable medium ofclaim 11, wherein the adjustment comprises an adjustment only to theaudio compression level.
 16. The non-transistory computer-readablemedium of claim 11, wherein the adjustment comprises an adjustment tothe video resolution level, the audio compression level and a framerate.
 17. The non-transistory computer-readable medium of claim 11,wherein the server is a network server.
 18. The non-transistorycomputer-readable medium of claim 17, wherein the network server employsa session initiation protocol for signaling.
 19. The non-transistorycomputer-readable medium of claim 11, wherein the server is operated bythe content provider.
 20. A server for performing a method ofdynamically adjusting a multimedia transmission between a contentprovider and a content recipient, comprising: the server configured to:receive an indication of a change in an available bandwidth between thecontent provider and the content recipient during an establishedmultimedia transmission of a multimedia stream that occurs at a videoresolution level, and an audio compression level; determine, based onthe change in the available bandwidth, an adjustment to at least of: thevideo resolution level or the audio compression level of the multimediastream; and coordinate the adjustment in the multimedia stream betweenthe content provider and the content recipient in the establishedmultimedia transmission.